Slightly over ten percent of U.S. children have some form of chronic illness. Although a family-centered approach to health care for these children has been advocated, existing systems of care have not adequately addressed the support needs of the family system and the essential role that parents play in the daily care of these children. The overall purpose of this two-phased program of research is to examine parent and family system adaptation to the care of a chronically ill child using a family stress and coping framework. Relationships among family system demands (stressers, strains, transitions, caregiving burden, child's illness actors) and family system strengths and capabilities (family type of family hardiness, resources of social support, appraisal, coping and problem-solving communication) will be examined to determine their separate and combined contribution to explaining the variability in parent and family system outcomes (parent well-being and family system adaptation) over time. The first phase will focus on the acute crisis illness stage in families with a child with congenital heart disease during the first year post diagnosis and in a comparison group of families whose child is screened for, but not diagnosed with, congenital heart disease. The second phase will focus on the long-term care illness stage (over one year post diagnosis) in two at-risk groups: families who have a child with congenital heart disease and a comparison group of families with a child with diabetes. Specific phase one aims are to 1) determine what family system demands and family system strengths and capabilities and combinations of these variables can best explain the variability in parental and family system adaptive outcomes during the acute crisis stage of the illness and how these factors and their importance change or remain stable over time; 2) determine commonalities and differences in these relationships for a comparison group of families whose child is screened for, but not diagnosed with, congenital heart disease. Phase two aims are to: 3) determine what family system demands and family system strengths and capabilities and combinations of these variables can best explain the variability in parent and family system adaptive outcomes during the long-term care stage of the child's illness and how these factors and their importance change or remain stable over time; 4) determine commonalities and differences in these relationships for a comparison group of families with children with another chronic illness, diabetes. Combining phase one and phase two results, aim 5) is to compare parent and family system variables (demands, strengths, capabilities and outcomes) in the acute crisis and long-term care stages of a child's chronic illness (congenital heart disease). A longitudinal design will be used to follow the two groups in each phase over two years. Multivariate analyses will be used to examine stability and change in within family, within group, and between group relationships over time.